Apparatus for making curved surfaces



Jan. 21, 1964 w. J. SMITH 3,118,215

APPARATUS FOR MAKING CURVED suRFAcE Original Filed April 4, 1958 2Sheets- Sheet 1 IN V EN TOR.

William JJmii'h BY @;,@@M

gen?" Jan. 21, 1964 w. J. SMITH 3,118,215

APPARATUS FOR MAKING CURVED SURFACES Original Filed April 4, 1958 2Sheets-Sheet 2 INVENTOR.

. William clSmjHz United States Patent 3,118,215 AlPARATUS FOB. MAKINGCURVE!) SURFACES William J. Smith, 1611 12th St, Gregor: (Iity, Greg.Qontinuation of application Ser. No. 726,436, Apr. 4, 1953. Thisapplication Sept. 20, 1961, Ser. No. 140,979 2 Claims. (ill. 29-27) Thisinvention pertains to lathes and like cutting and grinding apparatus,and relates particularly to apparatus by which to form spherical orother curved surfaces. This application is a continuation of my earlierfiled application, Serial No. 726,436 filed April 4, 1958 and nowabandoned.

In the operation of a lathe, for example, a piece of work is mounted forrotation on an axis and a cutting tool is moved along a straight lineparallel to the axis of rotation, whereby to form a cylindrical surfaceon the work. However, it is often desired to provide a piece of workwith a spherical or other curved surface, and it is the principal objectof the present invention to provide apparatus by which to form suchsurfaces.

Another important object of this invention is the provision of apparatuswhich may be utilized in cooperation with a conventional lathe, forpurposes of forming a curved surface on a piece of work.

A further important object of the present invention is the provision ofapparatus by which to form a spherical or other curved surface uponeither or both outer and inner surfaces of a hollow object.

A still further important object of the present invention is to provideapparatus for forming curved surfaces on an object, which apparatus isof simplified construction for economical manufacture and which isprecise in its operation.

The foregoing and other objects and advantages of this invention willappear from the following detailed description, taken in connection withthe accompanying drawings, in which:

PEG. 1 is a fragmentary view in side elevation of a conventional lathehaving mounted in cooperative relation therewith, apparatus embodyingthe features of the present invention;

FIG. 2 is a fragmentary sectional view taken along the line 22 in FIG.1;

PEG. 3 is a fragmentary sectional view taken along the line 33 in FIG. 1and showing details of construction of mechanism by which to form aspherical inner surface on a hollow object; and

FIG. 4 is a fragmentary view in side elevation "of the assembly shown inFIG. 3, as viewed from the bottom of FIG. 3.

Although the apparatus of the present invention may be provided in theform of a complete and integral unit, it is conveniently provided in theform of an attachment to a conventional lathe, and it is this embodimentthat is illustrated in the drawings. The lathe includes a base frame itwhich supports laterally spaced longitudinal ways 12 and 14, a rotarychuck 16 driven by a motor 18 for rotation on an axis substantiallyparallel to the longitudinal ways, and a tool carriage 29 mounted on theways for movement in the longitudinal direction of the latter, as bymeans of a rack and pinion assembly operable by a hand wheel 22. A toolcrossfeed normally is movable thereon as by means of a rack and pinionassembly operable by a micrometer handle 26.

The apparatus of the present invention includes a pair of longitudinallyspaced structural frames, each comprising the laterally spaced verticalsupports 28 and the horizontal top member 30. Although the verticalsupports may extend to the base which supports the lathe, and thus beindependent of the lathe, they are proportioned 3,113,2l5 Patented Jan.21, 1364 "ice in the embodiment illustrated for support upon the ways.Clamp elements 32 are removably secured to the bottom ends of thesesupports, as by means of the bolts 34, and they underlie the ways forsecuring the supports firmly to the lathe.

Mounted upon the transverse top members of the frame and extendinghorizontally therebetween is a structural member 36, preferably ofsubstantial dimension providing considerable weight and rigidity. Thismember is adjustable transversely land longitudinally with respect tothe supporting frames. Thus, transversely extending adjusting micrometerscrews 38 are secured in threaded lugs 4i projecting from the topmembers 30 of the frames, with the inner ends or" the screws abuttingthe structural member for securing the latter in transversely adjustedposition. Similarly, elongated adjusting screws 42 secured in thethreaded lugs 44 projecting from the underside of the structural member36 adjacent the opposite ends of the latter, function to abut thevertical frames and thus secure the structural member in longitudinallyadjusted positions.

Extending freely through a vertical opening in the structural member 35is a rotary post 46, the upper end of which is enlarged to provide aflange 48 which rests upon the upper surface of the structural memberand thus supports the post in a vertically suspended position. Anannular collar Sil is releasably secured about the post adjacent theunder surface of the structural member 36, as by means of the screwsillustrated, to prevent vertical displacement of the post.

A gear wheel 52 of substantial diameter is mounted upon this enlargedend of the post and secured thereto by means of the plate 54 and thesecuring bolts illustrated. Engaging the gear is a worm 56 which ismounted freely upon a shaft 58 journaled for rotation in the bearingsas, 62 supported by the structural member 36. One section 6 of a clutchis secured to the worm, while the cooperatin section 66 of the clutch iskeyed slidably to the spline 58 secured to the shaft 58. Axial movementof the clutch section as is effected by means of the hand lever 7t?which is mounted pivotally intermediate its ends on the pivot pin 72projecting from a bracket 74 secured to the structural member 36. Thelever is provided with a bifurcated yoke end 76 the spaced sections ofwhich are slotted to secure the radial pins projecting from a bearingmounted rotatably in a peripheral groove provided in the clutch section$5.

One end of the shaft is connected through the coupling 82. to the outputshaft 84 of a gear reduction unit 86, the speed and direction :of whichis adjustable by means of the hand wheel 88. The input shaft of the gearreduction unit is connected to a drive motor such as the electric motor99 illustrated.

A transverse bore is provided in the rotary post adjacent the lower endof the later for receiving the shaft 92 slidably therethrough. The shaftis secured against axial rotation within the bore by such means as thekey 94 which is secured to the shaft and is slidably received within akeyway formed in the post. A vertical plate 96 is secured intermediateits ends to the front end of the shaft, as by means of the bolts 98.Mounted in the plate adjacent its upper end is an elongated micrometerscrew llii), provided at its outer end with an operating handle 192. Thescrew is mounted in the plate for axial rotation but is constrainedtherein against longitudinal displacement. The screw extends through atransverse bore in the rotary post and is threaded through a projection194 secured to the post. Thus, as the handle is manipulated to rotatethe screw, the plate is caused to move in a vertical plane toward oraway from the post.

The lower end of the plate is provided with one or more threadedopenings adapted to receive the securing bolts 1%. A tool holder 1% isprovided with a slot lit} at one end adapted to receive the securingbolts, whereby to secure the tool holder firmly to the plate. Theopposite end of the tool holder is provided with a transverse openingadapted to receive a citting tool 112 therein, and a set screw 114 isprovided in the tool holder to releasably secure the cutting tool inadjusted position.

The operation of the apparatus thus far described, is as follows: Thestructural member 36 is adjusted laterally and longitudinally by meansof the adjusti g screws 38, 42 so as to position the rotational axis ofthe post :6 precisely on and normal to the rotational axis of the lathechuck 16, at the desired center of the spherical surface ,to be formed.The tool holder 1 525 is also adjusted vertically to position thecutting edge of the tool 112 on the proper cutting plane, as is Wellknown in the art. With the object to be surfaced mounted firmly in thelathe chuck, the tool is drawn into proper cutting relation with theobject by manipulation of the operating handle of the screw 1%. In thedrawings the object to be sofaced is shown to be a hollow metal castingin the form of a segmented sphere 116, provided wit a base 118 andprojecting plug 12% which is adapted to be secured firmly between thejaws of the lathe chuck.

With the lathe chuck being rotated by its motor and the cutting tool 112positioned at one end of the outer spherical segment to be surfaced, theelectric motor 963 is energized and the clutch sections 64, 66 engagedby manipulation of handle 7i thereby rotating the gear 52 and attachedpost 46 in the direction to move the cutting tool 112 arcuately towardthe opposite end of the spherical segment 11%, thereby forming a smoothand precisely spherical surface on the outer side of the object.

If it is desired to make another cut to reduce the diam eter of theobject, the direction of rotation of the post is reversed, either by useof a reversible electric motor or by the reversible gear reduction unitillustrated, and the second cut made either during such reverse rotationof the post, or, alternatively, the second cut may be made in the samedirection as the first cut, after the tool has been returned to itsinitial position.

Means also is provided for forming a curved surface on the inner side ofan object, either independently of or simultaneously with the formationof the outer surface. To this end there is provided a tool crossfeed 13hadapted to replace the conventional lathe tool crossfeed on the key 24.This tool crossfeed preferably is provided with the rack and pinionassembly of the conventional lathe tool crossfeed, for cooperation withthe operating handle 26. Thus, the tool crossfeed is rendered adjustablealong the key, transversely of the lathe ways, by the same meansnormally provided on a conventional lathe.

A longitudinal bore is provided in the tool crossfeed, the axis of thebore extending parallel to the lathe ways. The bore is adapted toslidably receive a shaft 132. therethrough, the latter being releasablysecured therein by such means as the set screws 134 carried by the toolcrossfeed.

The forward end of the shaft is slotted transversely to receive freelytherein the gear 136 and attached tool post 138. The gear and post aremounted for rotation Within the slot by means of the pivot bolt 14%which ex tends through aligned openings in the bifurcated ends of theshaft, the gear and tool post. A tool holder 142 is mounted adjustablyon the tool post as by means of the key 144 carried by the tool post anda cooperating key- Way formed in the tool holder, and is adjustable bymeans of the micrometer screw 14-6. The tool holder is slotted toreceive a cutting tool 143 therein, secured in positions of adjustmentby means of the set screw A shaft 152 extends freely through atransverse opening in the shaft 132, and carries a worm 154 which ispositioned for engagement with the gear 136. A bevel gear 156 is securedto one extending end of the shaft 152 for engagement with a second bevelgear 158 secured to the end of a drive shaft ldll which is mounted inbearings 162 supported by the tool crossfeed 136. Engagement of thebevel gears is achieved by adjusting the shaft 132 longitudinallythrough the bore of th tool crossfeed until the bevel gears mesh. Thisarrangement accommodates convenient disassembly of the parts.

The drive shaft is driven conventiently by connection to ii? shaft 5%,by means of the pulleys 164, 166 and belt 1-63. An idler pulley 17%) ismounted on a bracket s cured adjustably to the under side of thestructural member 36, and functions to engage and hold the belt 16% awayfrom the member 36. It will be understood that the idler pulley 17% maybe adjusted along the structural member and the pullleys 15 i and Planmay be adjusted along the shafts, to accommodate varying the position ofthe tool carriage 29 along the leng h of the lathe ways. Although thepulley res is shown to be releasably connected to the shaft 53 by suchmeans as a set screw, it will be understood that releasable coupling tothe may be provided by such means as the clutch asse ibly associatedwith the Worm as, previously described.

The operation of the internal cutting apparatus last described is asfollows: The lathe tool carriage 2% is adjusted along the lathe ways andthe tool crossfeed 13b is adjusted transversely thereof so as toposition the axis of the pivot bolt 14% precisely on the vertical ads ofthe spherical object 116 to be surfaced. It will be apparent that thisaxis will be the same as the axis of rotation of the post es. With thecutting tool 148 positioned initially adjacent the open end of thehollow object and the latter rotated by chuck lo, the drive motor 9i? isenergized to cause rotation of the shaft 163 through the belt and pulleyassembly. Rotation of this shaft causes simultaneous rotation of theWorm 15d and engaging gear $.36, thereby moving the cutting tool 148arcuate about the axis of pivot bolts Mill. in this manner the innersurface of the object is formed with a smooth and precisely sphericalsurface.

It will be appreciated that the inner and outer surfaces of the objectmay be acted upon by the cutting tools 148 and 112, respectively, eitherindependently of each other or simultaneously. If simultaneous cuttingsare desired, it may also be desired that the cutting tools traversetheir respective arcuate paths in substantially the same time. In suchevent the dimensions of pulleys, gears and worm assemblies may be chosento achieve this result, as will be apparent.

The apparatus is shown in the drawings arranged to form a sphericalsurface on the object 116. It will be apparent that other curvedsurfaces may be formed by various manipulations of the adjustablecomponents of the apparatus. For example, the spherical surface isprovided by arranging the rotational axis of the post 46 or pivot bolt14th normal to and intersecting the rotational axis of the chuck 16. Bydisplacing the rotational axis of the post or pivot bolt either side ofthe rotational axis of the chuck by adjustment of the screws 33, 42 andcrank 26, various non-spherical curved surfaces may be formed. Furthervariations may be made.

Although the apparatus illustrated employs cutting tools and 4 3 of thelathe turning type, other forms of tool may be used, such as grindingand polishing elements.

it will be apparent to those skilled in the art that various changes inthe details of construction described hereinbefore may be made withoutdeparting from the spirit of this invention and the scope of theappended claims.

Having now described my invention and the manner in which the same maybe used, what I claim as new and desire to ecure by Letters Patent is:

1. Apparatus for making a curved surface on a work piece, comprising abase frame, a work support mounted on the base frame for rotation on ahorizontal axis, spaced upright frame members mounted on the base frameembers, a post member supnorted on said structural member for rotationon a vertical axis, a tool support mounted on the post member forsupporting a tool radially outward from said vertical axis and radiallyoutward from the horizontal 2 118 of the Work support, drive meansmounted on the structural member and engaging the post member forrotating the latter, and adjustable connector means interengaging thestructural member and the spaced upright frame members for adjusting thestructural member longitudinally and laterally rela ve to the up 1.frame members for adjusting said ve .cal an of the ost memberlongitudinally and radiall' relative to the he; zontal axis of the Worksupport.

2. The apparatus of claim 1 including longitudinal ways on aid baseframe, a tool carriage mounted for longitudinal movement on said ways, acrossreed member 6 mounted for transverse movement on said toolcarriage, a shaft projecting from said crossfeed member, tool holdingmeans supported on the shaft for rotation on an axis substantiallynormal to the rotational axis of the work support, and adjustable driveconnector means interconnecting the tool holding means and the drivemeans for the post rnern References Cited in the file of this patentUNITED STATES PATENTS 84,697 Joyce Dec. 8, 1868 1,247,735 Stead Nov. 27,1917 1, 5,44 Maynard et a1 May 15, 1923 1,478,686 Teller Dec. 25, 19232,380,808 Tyson July 31, 1945 FOREIGN PATENTS 212,687 Switzerland Dec.15, 1940

1. APPARATUS FOR MAKING A CURVED SURFACE ON A WORK PIECE, COMPRISING ABASE FRAME, A WORK SUPPORT MOUNTED ON THE BASE FRAME FOR ROTATION ON AHORIZONTAL AXIS, SPACED UPRIGHT FRAME MEMBERS MOUNTED ON THE BASE FRAMEAND PROJECTING UPWARDLY BEYOND SAID HORIZONTAL AXIS, A RIGID STRUCTURALMEMBER SUPPORTED FREELY ON THE UPPER ENDS OF SAID FRAME MEMBERS, A POSTMEMBER SUPPORTED ON SAID STRUCTURAL MEMBER FOR ROTATION ON A VERTICALAXIS, A TOOL SUPPORT MOUNTED ON THE POST MEMBER FOR SUPPORTING A TOOLRADIALLY OUTWARD FROM SAID VERTICAL AXIS AND RADIALLY OUTWARD FROM THEHORIZONTAL AXIS OF THE WORK SUPPORT, DRIVE MEANS MOUNTED ON THESTRUCTURAL MEMBER AND ENGAGING THE POST MEMBER FOR ROTATING THE LATTER,AND ADJUSTABLE CONNECTOR MEANS INTERENGAGING THE STRUCTURAL MEMBER ANDTHE SPACED UPRIGHT FRAME MEMBERS FOR ADJUSTING THE STRUCTURAL MEMBERLONGITUDINALLY AND LATERALLY RELATIVE TO THE UPRIGHT FRAME MEMBERS FORADJUSTING SAID VERTICAL AXIS OF THE POST MEMBER LONGITUDINALLY ANDRADIALLY RELATIVE TO THE HORIZONTAL AXIS OF THE WORK SUPPORT.
 2. THEAPPARATUS OF CLAIM 1 INCLUDING LONGITUDINAL WAYS ON SAID BASE FRAME, ATOOL CARRIAGE MOUNTED FOR LONGITUDINAL MOVEMENT ON SAID WAYS, ACROSSFEED MEMBER MOUNTED FOR TRANSVERSE MOVEMENT ON SAID TOOL CARRIAGE,A SHAFT PROJECTING FROM SAID CROSSFEED MEMBER, TOOL HOLDING MEANSSUPPORTED ON THE SHAFT FOR ROTATION ON AN AXIS SUBSTANTIALLY NORMAL TOTHE ROTATIONAL AXIS OF THE WORK SUPPORT, AND ADJUSTABLE DRIVE CONNECTORMEANS INTERCONNECTING THE TOOL HOLDING MEANS AND THE DRIVE MEANS FOR THEPOST MEMBER.